Immune system : Built-in viruses could being hereditary immune memory
Our genetic material also contains remnants of old viruses. There is now evidence that they have a function in the immune system. Similar to CRISPR-Cas9 in bacteria, they could intercept viruses. by Lars Fischer © tracielouise/Getty Images/iStock (detail)
Virus genes built into the genome could represent a type of immune system that was believed to be lost. This is suspected by a working group headed by Emma F. Harding from the University of New & nbsp; South Wales in Australia based on an analysis of the RNA of marsupials. As the working group in & raquo; Microbiology Australia & laquo; writes, many of these so-called endogenous viral elements (EVE) have remained stable for millions of years, which suggests that they fulfill a function. The principle is possibly similar to the CRISPR-Cas9 system in bacteria, in which viral genetic material in the bacterial genome is used to intercept viruses and destroy their RNA. In this case, the EVE, which also make up about eight percent in the human genome, would be a kind of hereditary immune memory. However, this function has not yet been proven.
The team examined the EVE in the genome of 13 & nbsp; marsupials for their origin and activity & nbsp; & # 8211; so whether they will be translated into RNA. In fact, this is the case with some of these virus fragments, writes Harding's group. However, they are not translated into proteins. To do this, they resemble known antiviral RNAs that are part of the immune system in invertebrates and some plants. In fact, experts had assumed that this antiviral system was lost in mammals and replaced by the more effective interferon system. This is alerted by virus genetic material and triggers changes in body cells that fight viruses. In addition, research suggests other possible explanations. The discovery of the marsupials, however, suggests that the ancient system could continue to be active & nbsp; & # 8211; possibly also with us humans.